1. Field of the Invention
The present invention relates to a method of manufacturing a tubular body formed by a fine reinforced resin and the tubular body formed by the manufacturing method.
2. Description of the Related Art
In recent years, it has been desirable to develop a golf club shaft (hereinafter referred to as a shaft) capable of increasing a flight distance by a small force with an increase in the numbers of weak elderlies and woman golf players. In particular, a reduction in a weight of the shaft has been supposed to be one of effective means for solving the problem and various programs have been made.
As the programs, first of all, a change from steel to CFRP (carbon fiber reinforced plastic) can be taken in respect of a material. Also in the CFRP, a strength of a carbon fiber is enhanced, the physical properties of a resin are changed or a bonding strength of the carbon fiber and the resin is enhanced to increase a strength of the whole shaft, thereby reducing a weight correspondingly. As the program for the structure, moreover, the fiber is oriented or laminated at such an angle as to increase the strength so that the strength is increased to reduce the weight corresponding to the increase in the strength.
A tubular body formed by a fiber reinforced resin (which will be hereinafter referred to as an FRP tubular body) is used variously. For a method of manufacturing the FRP tubular body, a manufacturing method using a wrapping tape is well known. In the manufacturing method, a sheet-shaped FRP material is wound around a mandrel (cored bar) and a predetermined tension is then applied, and at the same time, a resin tape is wound therearound. In general, the resin tape is also referred to as a wrapping tape. A forming pressure is applied through the wrapping tape.
The wrapping tape is finally removed. In order to easily carry out the removal, a wrapping tape having a high mold releasing property is preferable. Japanese Laid-Open Patent Publication No. 2002-144439 has disclosed a wrapping tape having an internal surface in a fabric pattern in order to enhance the mold releasing property. More specifically, there has been disclosed a wrapping tape in which a fabric and a resin film are integrated with each other.